Method and device for authenticating a subscriber in a communications network

The invention relates to a method and an arrangement for Verification of authenticity of a first communication subscriber in a communication network.

In a communication network are generally data between Communication stations, for example, a service provider and a service user transmitted. To a communication network against the intrusion of unauthorized communication subscriber to protect in the communication network, Usually the authenticity of each communication participant checked.

From document [1] discloses a method and an arrangement for checking an authenticity of a communication subscriber, in particular of a service provider or a service user, known in a communication network.

The known from document [1] and the corresponding method known Arrangement is based on a so-called 3G TS 33.102 Version 3.0.0 Draft Standard, which is a security architecture describes a mobile radio system.

In <u><b>Fig.4</b></u> is the procedure for a review of a Authenticity of a communication subscriber as from is known to the document [1], and is typified hereinafter briefly and excerpts.

A transfer of data is in <u><b>Fig.4</b></u> each by a illustrated arrow. denotes a direction of an arrow a transmission direction during a data transmission.

<u><b>Fig.4</b></u> shows a mobile radio system 400, comprising a user 401 a communication service, for example, a Mobile phone, and a provider 402 of a communication service. The provider 402 includes a Einwählnetz 403 locally with a Einwählnetzbetreiber, where the user 401 a communication service requests, and a home network 404 with a home network, where the user 401 logged in and registered.

Further, the users have 401 Einwählnetz 403 and the Home network 404 each have a central processing unit with a memory, for example, a server (host) with which the processing unit described below is monitored and controlled procedure and are saved on which store data and / or are.

The Einwählnetz 403 and the home network 404, via a data line over which digital data can be transmitted, connected with each other. The user 401 and the Einwählnetz 403 over any transmission medium transmission of digital data connected to each other.

In a communication the user dials 401 in the Einwählnetz 403 410. At the start of a communication is carried out Review both the authenticity of the user 401 also the authenticity of the provider 402nd

These calls the Einwählnetz 403 so-called authentication data, with which the verification of the authenticity of the User 401 and the provider 402 is possible from the home network 404 to 411th

The authentication data, which determines from the home network 404 will include a random number and a sequential number Dealers 402. The sequential number of the Provider 402 is determined such that a counter of the offerer 402 with any attempt at communication between the user 401 and the provider 402, the sequential number of the supplier 402 is increased by the value 1.

It is to be noted that the random number sequence and the sequence number Dealers 402 only a portion of the authentication data are present and not exhaustive. Other authentication data are known from [1].

The home network 404 transmits the requested authentication data to the Einwählnetz 403 412. The Einwählnetz 403 processes the received authentication data appropriately Example 413 and transmits the processed authentication data to the user 401 414.

The user 401 checks using its own sequential number, which according to the sequential number Dealers 402 is handled, and the sequential number Dealers 402 the authenticity of the provider 402 415th

The procedure for checking the authenticity of the Provider 402 is described in [1].

A verification of the authenticity of the provider 402, "authenticity of the provider in order" 416, "Authenticity of the provider in order, but a sequence error occurred "417 or" not authenticity Dealers alright "418, is used by the user 401 to the provider 402 transmitted 419th

In the result "authenticity of the provider in order" 416 checks the Einwählnetz 403, as described in [1], the authenticity of the user 401 420.

In the result "authenticity of provider not OK" 418 communication is interrupted or restarted 421st

In the result "authenticity of the provider in order, but a sequence error "417 carried resynchronization so that the home network 404 a Resynchronisationsanfrage to the user 401 sends 422. The user responds with a Resynchronisationsantwort wherein resynchronization are transmitted to the home network 404 423. Depending on the Resynchronisationsantwort is the sequential number Dealers 402 424. Subsequently changed carried out the examination of the authenticity of the user 401, as it is known from [1].

The US-A-5,799,084 describes a method for checking the authenticity of a mobile station by a HLR / AC, wherein the mobile station from a Zufallszall and a sequence number, a first authentication message forms and sends it to the HLR / AC. The HLR / AC compares this message with a second, calculated by HLR / AC using a Zufallszall drawn from its authentication message.

The procedure described has the disadvantage that during an inspection of authenticity of a communication subscriber, especially when reviewing the authenticity a service provider, a lot of data between the communication subscribers must be transferred.

Thus, with respect to the invention is based on the problem, the known method and the known arrangement simplified and improved method and a simplified and improved arrangement for checking an authenticity a communication subscriber in a communications network specify.

The problem is solved by the method and by the assembly with the features of the independent claims dissolved.

In the method for verifying an authenticity of a first communication subscriber in a communications network is at the first communication subscriber using a fault detection data of the first communication subscriber and information on a random data a first defect information formed. In a second communication subscriber in the communication network, using a fault detection data of the second communication subscriber and the information about the random data, which has been transferred from the first to the second communication subscriber, a second error information formed, which is transmitted to the first communication subscriber. The first communication participant is calculated using the error information, the second fault detection data item of the second communication participant and the first fault detection data of the first communication subscriber übergrüft.

The arrangement for checking an authenticity of a first communication subscriber in a communications network is adapted for performing the method.

Under the review of the authenticity of a communication subscriber in a communication network are process steps to understand that in a broad sense with a review an authorization of a communication subscriber for access to a communication network or a participation carried out on a communication in a communication network will.

Thus, only those process steps are covered, which in Part of a review of the authorization of a communication subscriber performed for access to a communications network are, as also encompasses such steps, as part of a treatment or management of data, used in the review carried out will.

Preferred embodiments of the invention result from the dependent claims.

The embodiments described below relate both to the method and the arrangement.

The invention and further developments described below can both in software and in hardware, for example, by using a specific electric Circuit can be realized.

In one embodiment, the first communication subscriber a service provider and / or the second communication subscriber a service user in the communication network.

is preferably used as fault detection data a sequential number used.

In one embodiment, the information about the random data a random number.

In one development, the test of authenticity is characterized simplified in that a difference between the fault detection data the first communication subscriber and the Fault detection data of the second communication subscriber is determined.

In one embodiment, the verification of authenticity is characterized regarding the safety of the communication network further improved in that the difference is limited

Preferably, a further development is under a mobile radio system used. are In the mobile radio system / is the Service user as a mobile phone and / or the service provider as MNOs realized.

In figures, an embodiment of the invention is shown, which is explained in more detail below.

Show it<dl tsize="7"><dt>figure 1</dt><dd>a mobile radio system;</dd><dt>figure 2</dt><dd>a sketch in which symbolically a review an authenticity of a communication subscriber is shown;</dd><dt>figure 3</dt><dd>a flow diagram illustrating the individual process steps during an inspection of authenticity of a illustrated service provider in a communication network are;</dd><dt>figure 4</dt><dd>a sketch in which symbolically a review an authenticity of a communication subscriber presented in accordance with the 3G TS 33.102 Version 3.0.0-Standard is.</dd></dl>

Embodiment: Mobile System

In <u><b>Fig.1</b></u> 100 is shown a mobile radio system. The mobile radio system 100 includes a mobile telephone 101, a local Einwählnetz 102 with a Einwählnetzbetreiber 103 and a home network 104 with a home network operator 105th

In the home network 104, the mobile phone 101 is registered and registered.

Further, the mobile telephone 101, the Einwählnetz 102 and have the home network 104 each have a central processing unit 106, 107, 108 with a memory 109, 110, 111, with which Processing units 106, 107, 108 in the following is monitored and controlled procedure described and on which memories 109, 110, 111 data is stored and / or.

The Einwählnetz 102 and the home network 104 via a data line 112, transmitted via digital data can, together. The mobile telephone 101 and the Einwählnetz 102 over any transmission medium 113 for transmission of digital data connected to each other.

In <u><b>Fig.2</b></u> is the procedure for a review of a Authenticity of the mobile phone 101 and the procedure during an inspection of the authenticity of the home network 104 or the home network operator 105 shown symbolically and is described briefly below and excerpts.

A transfer of data is in <u><b>Fig.2</b></u> each by a illustrated arrow. denotes a direction of an arrow a transmission direction during a data transmission.

The in the following described and in <u><b>Fig.2</b></u> shown symbolically Approach is based on a so-called 3G TS 33.102 Version 3.0.0 standard, which is a security architecture describes a mobile radio system and described in [1] is.

In a communication, the phone dials 201 in the Einwählnetz 203 210. At the start of communication is performed a review of both the authenticity of the mobile phone 201 as well as the authenticity of the home network 204 or the home network operator.

These calls the Einwählnetz 203 authentication data, with what verifying the authenticity of the user 201 and the home network 204 and the home network operator possible is, from the home network 204 to 211th

The authentication data, which determines from the home network 204 will include a random number and a sequential number the home network 204 (see FIG. <u><b>Fig.3</b></u> Step 310). The sequential number of the home network 204 is determined in such a way that a counter of the home network 204 at each communication attempt between the mobile phone 201 and the home network 204 the sequential number of the home network 204 to the value 1 increases.

It is to be noted that the random number sequence and the sequence number the home network 204, only a portion of the authentication data represent and not to be understood are. Other authentication data are mentioned in [1].

The home network 204 transmits the requested authentication data to the Einwählnetz 203 212. The Einwählnetz 203 processes the received authentication data appropriately Example 213 and transmits the processed authentication data to the cellular phone 201 214th

The mobile phone 201 checks using its own Sequential number, which according to the sequential number of the home network is handled 204, and the sequential number the home network 204, the authenticity of the home network 204 215. According to the home network 204, the mobile phone 201 also includes a counter to.

The procedure for checking the authenticity of the Home network 204 is described in [1]. differing Process steps are described in the following.

As part of verifying authenticity of the home network 203 is a so-called overflow check the counter of the mobile phone 201 performed. This overflow checking is an overflow of the permissible number range of the counter the mobile phone 201 prevented.

In the overflow check the following conditions are checked:<sl><li>1) sequential number of the home network 204&gt; sequential number the mobile phone 201;</li><li>2) sequential number of the home network 204 - sequential number the mobile phone 201 &lt;predetermined deviation (here: 1000000);</li></sl>wherein the predetermined deviation applies:<ul><li>predeterminable deviation large enough in normal exclude or trouble-free communication mode, that:<sl><li>Sequential number of the home network 204 - sequential number the mobile phone 201&gt; predetermined deviation;</li></sl></li><li>Max. permissible sequential number of the mobile phone 201 / predefinable deviation is sufficiently large to prevent, that the max. permissible sequential number of the mobile phone 201 is achieved in operation.</li></ul>

A verification of the authenticity of the home network 204, "authenticity in order" 216, "authenticity OK, but a sequence error "217 or "Authenticity is not in order" 218, is from the mobile phone 201 transferred to the home network 204 419.

In the result "authenticity in order" 216 checks the Einwählnetz 203, as described in [1], the authenticity the mobile phone 201 220.

is In the result "authenticity wrong" 218 interrupted communication or newly started 221st

In the result "authenticity fine, but a sequence error occurred "217 carried resynchronization 222nd Under resynchronization is a change in the sequential number the home network 204 to understand.

For this, the mobile phone 201 transmits resynchronization to the Einwählnetz 203,222.

The resynchronization include the same random number, which was broadcast as part of the authentication data, and the sequential number of the mobile phone 201 (see FIG.<u><b>Fig.3</b></u> Step 320).

The Einwählnetz 203 processes the resynchronization data in suitable manner and transmits the processed resynchronization to the home network 204th

The home network checks the edited Resynchronization the sequential number of the mobile phone 201 and the sequential number of the home network 204 and optionally change the sequential number of the home network 204 223 (see FIG. <u><b>Fig.3</b></u> Step 330).

Then the home network transmits 204 new authentication data, which, where appropriate, modified sequential number the home network 204 include, at the Einwählnetz 203rd

To illustrate the described procedure are in <u><b>Fig.3</b></u> important steps 300 of the procedure shown.

<u><b>Fig.3</b></u> showing a first step 310, under which the determined authentication data (first failure information) will.

In a second step 320, the resynchronization will (Second failure information) determined.

As part of a third step 330, using the resynchronization, the sequential number of the mobile phone and the sequential number of the home network checks.

The following is an alternative of the first embodiment described.

In the alternative embodiment is a method realized with the home network against data loss is safer in a crash.

For this purpose, each in a predetermined time interval the current sequential number of the home network in the memory the home network stored. A case of a system crash the home network lost sequential number of Home network is restored so that the value to the stored sequential number a definable impact value is added. The predetermined charge value dimensioned such that the sum of the sequential number the mobile phone and not be predetermined deviation is exceeded.

In the alternative embodiment, the predeterminable Impact value is determined such that an average, from empirical values ​​during operation of the communication network certain number of authentication attempts someday the home network multiplied by a factor with a value of 10 becomes.

In this document, the following publication is cited:<sl><li>[1] 3G TS 33.102 version 3.0.0 Draft Standard, 3^rd generation Partnership Project, Technical Specification Group Services and System Aspects, 3G Security, Security Architecture, 05/1999.</li></sl>